It is known to use filter screens in fuel injection systems for filtering foreign material from the fuel so that such foreign material does not reach vital parts of the fuel rail assembly. The potentially adverse consequences of particulate material entering a fuel injector, or other operative component of a fuel rail assembly, have been documented and need not be repeated here. It also known to use cartridge type fuel filter elements in fuel systems. However, insofar as the Applicant is aware, it has not heretofore not been proposed to use a tubular filter cartridge as a discrete element replaceably mounted in its own socket in a fuel rail for filtering foreign material from fuel before the fuel reaches vital components of the fuel rail assembly.
The present invention relates to the incorporation of a tubular filter cartridge in its own socket in a fuel rail and to a number of novel, advantageous features via which the filter cartridge is associated with a fuel rail. These features include: the integration of a tubular filter cartridge into a cylindrical cartridge housing that separably mounts in its own socket in the fuel rail to allow for removal and replacement; the incorporation of certain features on the exterior of the cartridge housing to provide a secure fit of the housing within the fuel rail socket; the incorporation of certain features that provide a convenient flow path for the fuel being filtered; and fluid-tight joints between the cartridge housing and the socket. In one particular embodiment, the cartridge housing includes an inlet connector fitting (an example being a so-called quick connect fitting) that is integrally formed with the cartridge housing and provides for connection of a fuel supply conduit to the fuel rail assembly. In another particular embodiment, the filter cartridge is not contained within a cartridge housing but rather is disposed directly within the fuel rail socket and retained therein by means of a closure plug that removably closes an open end of the socket to capture the filter cartridge in the socket in a secure and sealed manner.